Artigo
Spin-orbit coupling for tidally evolving super-Earths
Fecha
2012-12-01Registro en:
Monthly Notices of The Royal Astronomical Society. Hoboken: Wiley-blackwell, v. 427, n. 3, p. 2239-2250, 2012.
0035-8711
10.1111/j.1365-2966.2012.22084.x
WOS:000311414800028
WOS000311414800028.pdf
Autor
Universidade de São Paulo (USP)
Universidade Estadual Paulista (Unesp)
German Aerosp Ctr DLR
Resumen
We investigate the spin behaviour of close-in rocky planets and the implications for their orbital evolution. Considering that the planet rotation evolves under simultaneous actions of the torque due to the equatorial deformation and the tidal torque, both raised by the central star, we analyse the possibility of temporary captures in spinorbit resonances. The results of the numerical simulations of the exact equations of motions indicate that, whenever the planet rotation is trapped in a resonant motion, the orbital decay and the eccentricity damping are faster than the ones in which the rotation follows the so-called pseudo-synchronization. Analytical results obtained through the averaged equations of the spinorbit problem show a good agreement with the numerical simulations. We apply the analysis to the cases of the recently discovered hot super-Earths Kepler-10?b, GJ 3634?b and 55 Cnc?e. The simulated dynamical history of these systems indicates the possibility of capture in several spinorbit resonances; particularly, GJ 3634?b and 55 Cnc?e can currently evolve under a non-synchronous resonant motion for suitable values of the parameters. Moreover, 55 Cnc?e may avoid a chaotic rotation behaviour by evolving towards synchronization through successive temporary resonant trappings.